Absorbent product such as a sanitary towel, a panty liner or an incontinence pad, which product has two transverse end edges, two longitudinal side edges, a liquid-permeable surface layer, a liquidtight backing layer and an absorbent core arranged between these layers, the product having side flaps arranged at the longitudinal side edges on both sides of the absorbent core, which side flaps are of such shape and size that, during use of the product, they can be folded around the leg edges in the crotch portion on a pair of briefs.
Modern conventional absorbent articles either have side flaps or do not. The purpose of the side flaps is to be folded around the edges of the briefs in the crotch portion and in this way help to ensure good fastening of the article in the briefs so that the article does not lie askew. An example of a document which describes the importance of side flaps for the fastening of an absorbent article is EP 0 359 501. A further reason for providing an absorbent article with side flaps is that the risk of leakage occurring is reduced. Leakage often arises in articles without side flaps when the edges of the briefs in the crotch area become folded in over the top side of the article or when the article has ended up askew in the briefs. This usually happens when the article is narrower than the width of the briefs. Leakage can also occur when the bodily fluid cannot be absorbed in time by the central portion of the article but runs out and over the side edges of the article where the bodily discharge comes into contact with the briefs. An article with side flaps ensures the positioning of the article in the briefs and reduces the occurrence of leakage. In order to reduce the leakage along the sides of the article, the article is advantageously provided with side flaps which are as long as possible along the longitudinal side edges of the article. Examples of articles with long side flaps are described in, for example, WO 98/25564 and EP 0 928 179. However, many wearers feel an article with conventional side flaps is insufficiently inconspicuous, because the side flaps are visible on the outside of the briefs. This is of course more marked, the larger the side flaps are. An article which does not have side flaps is in this respect much more discreet as no side flaps have been folded around the briefs in the crotch area. However, leakproofness is inferior in such an article. Articles without side flaps are therefore most often recommended for use when smaller flows of liquid are to be received by the article. Manufacturers of sanitary articles have traditionally used material which has a whitish colour In order to give the consumer a feeling of freshness with the article and in order to be suitable for white briefs, which has been the most common colour of briefs on the market. The market has changed now, and there is a wide variety of briefs with both different colours and different patterns, which means that white side flaps or side flaps of a colour different from that of the briefs are clearly visible on the outside of the briefs. Many people take part in sports which require a change of clothes in an environment which is to a greater or lesser extent public. In this connection, it is virtually impossible to conceal the use of a sanitary protection means with side flaps because these are visible on the outside of the briefs. The same problem arises in the case of activities such as swimming and sunbathing. There is also a requirement among some users of sanitary articles to be able to conceal the use of these in their home environment as well.
There have been attempts to solve the above problems by making the side flaps transparent. EP 1 138 293 discloses an absorbent article that shows transparent areas. However, transparency is not the same as non-visibility. The side flaps, even if they are made in a transparent material, can shine and in that way be visible. In addition, it is not necessary for the side flaps to be transparent for them to be experienced as invisible. On the contrary, a very transparent material is often very shiny.
Thus, there still is a need for an improved absorbent article with side flaps and enhanced discretion.
By means of the present invention, a product of the type referred to in the introduction has been produced, which product essentially eliminates the problems associated with previously known such products.
A product made according to the invention is principally characterized in that the side flaps exhibits a gloss below 25% and a regular transmittance above 5%. By making the side flaps exhibit a gloss below 25% and a regular transmittance of above 5%, enhanced inconspicuousness is achieved for the wearer on occasions when the wearer is seen wearing only patterned and/or coloured briefs, or sun clothes, without forgoing the leakproofness of the article,
Preferably, the side flap exhibit a gloss between 3 and 10%. Most preferred is a gloss of 6%. Gloss is measured according to ASTM 2457-97. What is measured is how the material reflects light. The side flaps are experienced as being invisible when the gloss of the material in the side flaps is below 25%, provided that the material is transparent enough. Perforating the side flaps would affect the gloss so that it is decreased. However, it is difficult to measure gloss using the above method on a material that has a lot of holes. A material with a nominal value of gloss that is higher than acceptable, can be chosen if it is later perforated. The relationship between the gloss of a non-perforated material and the same material perforated, can be presumed to be linear as a function of the nominal gloss of the material. If a non-perforated piece of material has a gloss of a certain value, and that piece of material is perforated, the piece of material obtains a gloss that is a function of the starting gloss value and the open area of the perforated piece of material. That is, perforated materials are also a part of the invention. The starting point is as described above, the gloss of a non-perforated piece of material. The open area that the piece of material achieves when it is perforated then reduces that value. The value of gloss of the perforated material can be described by the following equation:
Gp=Goxc3x97f[(Atotxe2x88x92Ahole)/Atot]
Where
Gp=gloss of the perforated material
Go=gloss of the non-perforated material
f=a linear function
Atot=total area of the piece of material
Ahole=total area of holes of the piece of material
A material with a gloss that is higher then acceptable can also be chosen if it is later embossed. The gloss of an embossed material is not difficult to measure. A laminate comprising an upper perforated layer and a lower nonperforated layer is also readily measurable.
A higher gloss of the side flaps than 25% would be acceptable, or even desirable, in cases where very glossy briefs are used, such as specific types of polyester or silk. However, this type of underwear is a minority of the underwear existing and that area is not the subject for this invention.
According to a preferred embodiment of the invention, the side flaps exhibits a transmittance of above 10%. It can be preferred to make the side flaps in a material that has a regular transmittance below 90%. Above this value of the regular transmittance, a material often exhibits too high gloss to be experienced as invisible compared to a material having a regular transmittance below this value. The transmittance is measured according to ASTM D 1746-97, on a non-perforated piece of material.
According to a preferred embodiment of the invention, the side flaps are constituted by the liquidtight-backing layer which extends beyond the longitudinal side edges of the product. In this connection, a liquidtight transparent backing layer can be treated in the area of the absorbent core so that the surface within this area has greater opacity, that is to say is less transparent. The liquidtight transparent material can, for example, be coloured, provided with a colour print or stamped so that the material becomes less transparent. Such treatment may be desirable given that some users find it off putting when it is possible to see into the core of the absorbent article. This problem is especially marked when the absorbed bodily liquid is reddish menstrual fluid.
According to another embodiment, the article has been provided with an opaque layer on that side of the absorbent core which faces away from the wearer during use. This layer can be constituted by an opaque fastening means in the form of adhesive fastening glue, a mechanical fastening means or a separate layer in the form of an opaque non-woven material, plastic layer, laminate or the like. According to a fourth embodiment, the side flaps consist of a separate material layer or laminate which is positioned and attached across the article on the inside or the outside of the liquidtight backing layer. According to a further embodiment, the side flaps consist of at least two separate material layers which are attached to the longitudinal side edges of the article. It has also been found to be advantageous if the transparent side flaps also have an adhesive fastening means adjacent to the outer contour line of the side flap in order to bring about good contact with the briefs so that the side flap does not hang down from the briefs and thus become conspicuous.